1. Field of the Invention
The present invention relates to a recording apparatus which records an image by discharging ink from a recording head and a pattern recording method executed by the recording apparatus.
2. Description of the Related Art
An inkjet recording apparatus includes a platen on which a recording medium is placed and a recording head which faces the platen and executes scanning in forward and backward directions and performs recording on the recording medium by discharging ink thereto while scanning with the recording head. Particularly, the inkjet recording apparatus can perform high speed recording by discharging ink while scanning in both of a forward direction and a backward direction, which is referred to as bidirectional recording.
However, when a distance between a surface on which an ink discharge port of the recording head is disposed and a recording medium (i.e., referred to as “a paper gap”) varies in a scanning direction, a deviation occurs between an impact position of an ink droplet discharged in the forward direction and an impact position of an ink droplet discharged in the backward direction.
Japanese Patent Application Laid-open No. 2006-015678 has discussed a technique for recording a test pattern for adjusting impact positions of ink droplets in the forward and backward directions across the entire width in a scanning direction of a recording area on a recording medium. The invention described in Japanese Patent Application Laid-open No. 2006-015678 corrects discharging timing of at least one of the forward and backward directions to minimize an average value of deviation amounts at respective positions. Accordingly, the deviation of the impact positions of ink droplets in the scanning direction is decreased.
In addition to the above recording position deviation between the forward direction and the backward direction, many kinds of a recording position deviation such as a recording position deviation among nozzle arrays and a recording position deviation caused by nozzle arrays inclination are considered as the impact position deviation (i.e., the recording position deviation) occurring at the inkjet recording apparatus. Regarding these items, it has been required to record a test pattern for a plurality of items in the scanning direction to record the test pattern in a shortest time on fewest recording sheets.
A commonly-used inkjet recording apparatus supports a plurality of types of recording sheets of different sizes in the scanning direction such as an A4 size which is most popular plain paper for recording documents, a letter-size, an L-size which is most popular photo-dedicated paper for recording photo images, and a 4×6 size. With such a recording apparatus, it has been desired that a recording position deviation is appropriately adjusted at a recording sheet which is relatively small-sized in the scanning direction such as L-size and 4×6 size and specially required high quality photo recording.
However, Japanese Patent Application Laid-open No. 2006-015678 has discussed the technique for recording a test pattern for adjusting impact positions of ink droplets in the forward and backward directions across the entire width in the scanning direction but has not discussed about recording a test pattern for a plurality of items in the scanning direction. Further, there is no discussion about appropriate adjustment of the recording position deviation corresponding to a recording sheet which is relatively small-sized in the scanning direction when recording is performed on a plurality of types of recording sheets having different sizes in the scanning direction.